The work and pensions secretary, Iain Duncan Smith, has proposed a shakeup of the welfare system with a new 'universal credit'. Photograph: Matt Cardy/Getty Images

Reasons for claiming benefits haven't changed much over the years. Many of us will face circumstances that affect our ability to earn money. Illness, care of a child (or an adult), disability, unemployment and old age.

The system that protects us in these circumstances has evolved into a bureaucratic nightmare. Expensive to administer, with bewildering contradictions in the conditions of multiple benefits. Conditions often underpinned by assumptions of laziness, immorality, and the dishonesty of the claimant.

When you take the circumstances that lead to benefit claims, survival on benefit rates, the complexity of the system and the stigma that comes with needing state help, a temporary period of unemployment in the wrong circumstances can result in years of exclusion from the labour market.

When Iain Duncan Smith says that this system traps people, I agree. It would be foolish to argue against his proposed "universal credit". One benefit instead of the 51 that currently exist (including tax credits). A "credit" that would bring together taxation and benefits, remove the stigma of claiming and allow people to move between unemployment and work without jeopardising their household's economic stability? Radical welfare reform is long overdue. This consultation is just what we need. Brilliant. Shouldn't I be jumping for joy?

There isn't much in the way of detail in this document. Economic realities like rents, wages, childcare costs or the state of the labour market rarely feature in research by the Centre for Social Justice. They concentrate on how a family should be: married mothers staying at home, dependent on their husbands. The cap on the "upper level" of tax credits already ensuring the choice of returning to work is denied to many new mothers in low-earning families.

Outside consultation documents, the coalition doesn't use the language of thoughtful reform. Housing benefit cuts that threaten hundreds of thousands of working families with homelessness are justified as preventing a fictitious family of "scroungers" from living in a hypothetical mansion. How the employment prospects of the 88% of local housing allowance (LHA) claimants who aren't unemployed and still need help with their housing costs will be improved by the threat of homelessness is a puzzle.

When this is added to the promised removal of the "couples penalty" from the benefits system, it is becoming less likely that a single mother, like myself, of young children would be able to meet her basic living costs by working (although Frank Field has made assurances that if the woman should return to financial dependence on a man she would feel some economic benefit). The equalities minister, Patricia Hewitt, does not appear to think these cuts are relevant in her attempts to tackle the "scourge of domestic violence".

The Fawcett Society's legal challenge to the budget has highlighted the scant consideration of the effect of these cuts on women and children, and when the plan for a universal credit was last costed, it was estimated that it would run to £7bn not £3bn. The Institute of Fiscal Studies can't see how "work incentives" can be strengthened without spending more money, or "hurting the poor".

Reassuring as the words accompanying this consultation are, it appears that yet again they are just words – with the reality behind them likely to hit the most vulnerable, hardest.